Hydraulic actuator



Dec. 6, 1966 H. M. PURCELL 3,239,549

HYDRAULIC ACTUATOR I Filed April 14, 1964 5 Sheets-Sheet l INVENTOR.

HOll/HRD M- PURCELL Dec. 6, 1966 H. M. PURCELL 3,289,549

HYDRAULIC ACTUATOR Filed April 14, 1964 5 Sheets-Sheet 2 F G 5 1 INVENTOR.

HOWARD M. PURCELA Dec. 6, 1966 M. PURCELL HYDRAULIC ACTUATOR 5 Sheets-Sheet 5 Filed April 14, 1964 FIG IN VENTOR.

u m u P M. 0 m w 0 H United States Patent 3,289,549 HYDRAULIC ACTUATOR Howard M. Purcell, South Euclid, Ohio, assignor to Ashtabula Bow Socket Company, Ashtahula, ()hio, a corporation of ()hio Filed Apr. 14, 1964, Ser. No. 359,737 2 tClaims. ((11. 91-402) This invention relates to hydraulic motors, particularly paddle type motors and to uses thereof and to circuitry involving such motors.

There are many instances in which hydraulic motors are employed for imparting a relatively short stroke to a work member, including imparting oscillatory movements to work members within predetermined limits.

Usually reci-procable hydraulic motors consisting of cylinders and pistons therein are employed for this service, but motors of this nature are relatively expensive and tend to leak at the rod end thereof and, furthermore, when employed for oscillating members work through a moment arm which varies and is many times shortest when the motor is required to develop the greatest power.

A particular instance where reciprocable hydraulic motor are employed and operated under the disadvantageous conditions, as outlined above, is in connection with the operation of the tops of convertible auto-mobiles. When reciprocable motors are employed for actuating the tops between their collapsible and raised positions, the moment arm through which the motor works is shortest at opposite ends of travel of the top and at which time the maximum power is required,

Such automobile tops require a motor at each side and the possibility arises that one of the motors will leak or will permit some slippage past the piston which will permit the motors to get out of step, whereupon the top being actuated will be twisted. It has been proposed to connected motors of this nature in series so'that the displacement from one will actuate the other and, in this manner, the motor will be completely in step but this requires that two motor of different sizes be manufactured and used on each convertible automobile.

The present invention is particularly concerned with the provision of an improved hydraulic motor having many possible uses, but particularly adapted for use for actuating automobile convertible tops.

An object of this invention is the provision of a paddle type hydraulic motor which is exteremly inexpensive to manufacture.

Another object is the provision of a paddle type hydraulic motor which is substantially free of leakage.

Still another object of the present invention is the provision of a novel hydraulic motor particularly adapted for actuating the tops of convertible type automobiles.

Still another object of the present invention is the provision of an improved actuator for actuating the convertible top of an automobile and a novel hydraulic circuit embodying the actuator.

These and other objects and advantages of this invention will become more apparent upon reference to the following specification taken in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view showing a convertible type automobile having a top to be actuated between raised and lowered positions.

FIGURE 2 is a fragmentary perspective view showing a portion of the top structure and an actuating motor according to the present invention connected thereto.

FIGURE 3 shows the actuators pertaining to a convertible top connected in a hydraulic circuit.

FIGURE 4 is a sectional view on line 4-4 of FIG- URE 2 showing the actuator according to the present invention in longitudinal cross section.

FIGURE 5 is a sectional view indicated by line 5-5 on FIGURE 4 showing the actuator in transverse cross section.

FIGURE 6 is a cross sectional view indicated by line 6-6 on FIGURE 5.

FIGURE 7 is a perspective view showing the manner in which a. rubber like seal is provided on the paddle portion of the motor for sealing it in the motor casing.

FIGURE 8 is a cross sectional view showing a modified arrangement.

FIGURE 9 is a sectional view indicated by line 9-9 on FIGURE 8.

FIGURE 10 is a fragmentary view showing a modification.

FIGURE 11 is a fragmentary sectional view showing a modified construction embodying a double-acting stroke limiting check valve arrangement; and

FIGURE 12 is a fragmentary perspective view showing more in detail the construction of the check valve of FIGURE 11.

Referring to the drawing somewhat more in detail in FIGURE 1, 10 indicates an automobile having a collapsible convertible top 11 which is actuated between raised and lowered positions by a hydraulic actuator at each side of the vehicle toward the rear with one thereof being indicated at 12 in FIGURE 1.

FIGURE 2 shows a portion of the vehicle body 13 with the actuator 12 mounted thereon and with a plurality of links 14 forming a part of the structure of the vehicle top also being illustrated.

The motor 12, as will be seen in FIGURES 4, 5 and 6 comprises an outer casing part consisting of the portions 15 and 16 which meet in the middle plane of the actuator and which are welded together by welding 17 extending completely around the housing of the actuator. The housing parts are advantageously formed by a stamping and forming process so that they are quite inexpensive to produce.

The completed housing is sector shaped and swingably mounted therein is a paddle or vane member 18.

The vane member or paddle consists of two identical metal portions 19 secured together in face to face engagement by welding 20 and at one end, namely, at the region of the apex of the sector shaped housing are formed to receive a pivot shaft 21 secured to the parts 19 by welding 22.

The parts 19 making up the paddle have marginal edges flared outwardly as indicated at 23 to form a channel extending completely around the periphery of the paddle on opposite sides of shaft 21 and dividing around the shaft. The channel can best be seen in FIGURE 7 which shows a perspective of the paddle. This channel is availed for receiving a rubberdike sealing strip 24 which is made in a single piece and which is formed with two rectangular portions 25 that fit in the channel on the long side of the paddle and across the end thereof and around the ends of shaft 21 and with there being a bar-like element 26 extending transversely between the inner ends of the portions 25 so as to extend across the bottom of the vane.

The sealing member also includes the substantially triangular projections 27 which overlap on the side of the shaft toward the long portion of the paddle and seal at that region along the paddle adjacent the shaft.

The metal parts 19 of the vane or paddle fit relatively closely within the housing with a cleanance of only two or three thousandths and the rubber-like sealing member extends slightly out from the paddle on all sides and presses against the inside of the housing and, thus, divides the housing into separate compartments. When the paddle swings within the housing, the oil within the housing will lubricate the rubber-like sealing strip so that it will move relatively easily on the smooth metal of the housing.

I have found that by controlling the welding operation, the housing parts can be sealing fused together by the welding 17 without warping the housing and without distorting the parts of the housing along the joint on the inside.

The shaft 21 extends through holes provided therefor in parts and 16 of the housing and has outer end portions 28 formed for driving engagement with actuator arms 29 which are tbolted as by bolts 30 to one of the members 14 of the top to be actuated. The actuator arms 29 may be retained on shaft 28 in any suitable manner, such as by way of nuts 13 screwed on the ends of the shaft.

Each housing part, as will be seen in FIGURES 4 and 6 has an adjustable abutment screw 32 in one of the side walls locked in place by nut 33 to provide an adjustable abutment for the paddle when moving toward the said screw. Each housing has a port 34 in the other side wall for receiving the end of a conduit 35 which supplies oil to the adjacent compartment and which conducts oil therefrom. In this manner, an adjustable stop is provided for the paddle in each direction of movement thereof and means are provided for supplying oil under pressure to each side of the paddle while exhausting oil from the other side thereof.

As will be evident, the paddle and its shaft, together with the sealing member thereon, must be placed within the housing prior to welding the two parts of the housing together. The welding together of the housing can be accomplished without damaging the seal element, however, by placing the paddle in a predetermined position and welding portions of the housing together remote therefrom and then chilling the welded portion and shifting the position of the paddle and, thereafter, welding together the remainder of the same between the housing parts.

A paddle motor, according to the present invention, can be connected in circuit as shown in FIGURE 3, wherein a reversible pump is driven by an electrical reversible motor 41 under the control of a switch 42. Pump 49 has one port connected by conduit 43 with one of the ports of a shaft actuator 44 positioned at one side of the vehicle top and the other port of the pump is connected by conduit 45 to the oppositely disposed inlet port of actuator 46 on the opposite side of the car. A conduit 47 interconnects the other ports of the actuators.

Rotation of pump 40 in one direction will supply pressure fluid to conduit 43 and this will drive actuator 44 in one direction and actuator 44 will displace fluid under pressure to conduit 47 which will supply fluid to actuator 46 to drive it in the same direction as actuator 44. The fluid displaced from actuator 46 is returned via conduit 45 to pump 40. The actuator displaces actually the same amount of fluid in both direction of movement so that two identical actuators can be connected in series as shown and provide for equal movement of the shafts of the actuators. Each actuator is stopped in both directions of movement either by the mechanism which it actuates or by the stop screws 32.

FIGURES 3 and 6 show a modided arrangement contemplated wherein the paddle of each actuator, near each end of its working movement, uncovers a restricted port 50. Each restricted port is connected by a small conduit 51 through a non-return valve 52 with the adjacent main conduit. The ports have no influence on the operation of the actuators until the paddles uncover the ports. When the paddles are moving in the direction toward the said ports and even after the ports are uncovered only a small amount of fluid will by-pass through the respective port 56*.

.By this arrangement, if one motor should slip on account of fluid leakage passed the paddle, the motor will again move into step at the end or each operative cycle because the leading motor will come to a halt and fluid will, then, by-pass through the pertaining port 50 to cause the other motor to continue its movement to the end of its stroke, The provision of the auxiliary port 50 is provided where it is important for the motor to be brought back into step periodically. Alternatively, the valves 52 could be manual valves and be opened only when the occasion required for the motor to be brought back into step.

FIGURE 10 shows another arrangement for keeping the motors in step where they come to a stopped position at each end of their travel. This modification comprises the provision of a small port 60 in each paddle which, will not materially effect the operation of the motors, will permit a small amount of fluid to bleed through each paddle so that one motor can be brought to a halt at the end of its travel and a trailing motor associated therewith in series will be permitted to continue its movement to the end of its stroke.

FIGURES 8 and 9 show an arrangement where the chambers on opposite sides of the paddle can be interconnected and wherein a bleed passage between the chambers can be established.

This is accomplished by axially drilling the motor shaft with a shouldered bore 61 which is communicated on one side of the shoulder with the chamber on one side of the paddle by bore 62, while on the other side of the shoulder a bore 63 communicates with the chamber on the other side of the paddle. A valve member 64 is provided threaded into bore 61, and having a position wherein the end 65 engages shoulder 66, thus, preventing communication between the compartments on opposite sides of the vane. The screw can be backed up to provide for relatively free communication between the compartments or can be adjusted to provide for a bleed passage continually communicating the compartments.

In FIGURES 11 and 12, the paddle motor illustrated has a casing and a paddle 81 therein the same as in the previous modifications. Conduit means connected at 82 and 83 to the side walls of the casing supply pressure fluid to one side or the other of paddle 81 for causing it to move in the casing. The paddle has a hole 83 punched therein which, as will be seen in FIGURE 12, has a pair of diametrically opposite circular regions 84 and notched out portions 85 between the circular regions.

Mounted in hole 83 is a double check valve arrangement which includes a central shank 86 which may fit circular regions 84 relatively closely while permitting free reciprocation of the check valve in the hole. Shank 86 has substantially conical head means 87 and 88 thereon, one of which may be integral with the shank and the other fixed thereto in any suitable manner. Between each said portion and the adjacent side of the paddle is an O-ring 89. The arrangement is such that whenever pressure fluid is applied to one side of the paddle the check valve will be thrust toward the paddle on that side and sealingly engage the adjacent Oring. When the paddle approaches the end of its travel, however, the leading end of the check valve member will be engaged by the side wall of the casing that the paddle is approaching and this will force the check valve member toward the paddle and establish a passage through the paddle for pressure fluid. The paddle can thus come to a halt while the flow of fluid continues. If only a single motor is being used the pump will be by-passed directly to exhaust and the pressure in the system will be dropped and the pump motor will run relatively light. The positioning of the paddle, however, is relatively precise so that the check valve serves as a stroke limiter.

Where two paddle motors are used in series, as shown in FIGURE 3, either motor, upon reaching the limit of its travel, will stop and the other motor will continue under full power until the end of its travel and will, then,

come to a halt and at that time the pressure in the system will drop and the pump motor will, then, run light. Reversal of fluid flow to the motor or actuator can be accomplished at any time and the check valve will automatically close to prevent an escape of fluid through the paddle except when the paddle is in a limit position.

By the arrangement of FIGURES 11 and 12 the stopscrew for stopping the paddle can be eliminated and the slippage of one motor or actuator relative to the other becomes a matter of small importance because the trailing motor will catch up with the leading motor at the ends of the strokes thereof on each cycle.

The arrangement according to the present invention, is compact and inexpensive and developes a substantial amount of power and developes uniform power throughout its stroke without the disadvantage of a changing moment arm; is easy to construct and seal. The low expense of the actuator makes it possible to use it as a throw-away item that can be discarded economically and replaced by a new one in the event it becomes defective, for any reason.

With respect to the double check valve arrangement of FIGURES 11 and 12, it is contemplated that this valve arrangement could also be used in a reciprocable hydraulic motor by mounting the arrangement in the piston and operating the valve arrangement by the opposite end Walls of the cylinder in which the piston is moved.

This corresponds substantially with what is illustrated in FIGURE 11, with the exception that the moveable element would take a linear path in the hydraulic cylinder rather than the arcuate path taken by the vane in the hydraulic actuator according to the present invention. able element will move under full power to the limit of its stroke and thereafter the actuating fluid will be bypassed through the moveable element, thus resulting in a drop in system pressure and also permitting other actuators in series with the actuator at its limit position to continue on to their limit position and under full power.

It will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions; and accordingly, it is desired to comprehend such modifications Within this invention as may fall Within the scope of the appended claims.

I claim:

1. A hydraulic actuator comprising; a casing substantially sector shaped in longitudinal cross section and rectangular shaped in transverse cross section, a shaft extending into the casing substantially at the apex of said casing, a paddle in the casing sealingly fitted in the casing and fixed to said shaft, and conduit means for selectively admitting pressure fluid into and from said casing on respectively opposite sides of said paddle effective to rotate said shaft, said casing comprising two substantially identical sector shaped portions, having upstanding peripheral walls, said portions being placed together with the respective walls substantially coplanar and in engagement, and means sealingly rigidly connect ing said walls together, said paddle having groove means extending completely around the edge of the paddle and including portions extending around opposite sides of the shaft, and resilient seal means in said groove means to seal the paddle to the interior walls of the casing and including the region thereof around said shaft, said paddle comprising two substantially identical members having marginal steps thereon and placed together in face to face engagement so the said steps cooperate to form said groove means, means fixedly securing said members together and to said shaft, port means in the said casing In both cases, the advantage exists that the move-.

located adjacent each terminal position of said paddle and which the paddle passes over in moving into its respective terminal positions, said port means being connected with said associated conduit means and a check valve connected to each port means permitting fluid flow from each port means in a direction away from said casing only.

2. In a convertible type automobile which has a collapsible top structure and link means movable to raise and lower said structure; actuator means adapted to move said link means comprising a pair of hydraulic actuators mounted on a fixed structure, each of said actuators comprising a casing substantially sector shaped in longitudinal cross section and approximately rectangular shaped in transverse cross section and forming an inner chamber, the two chambers having equal volumetric fluid capacity, a shaft extending into each casing substantially at the apex thereof, a paddle in each casing sealingly fitted therein and fixed to its associated shaft, each said shafts being adapted to be operatively connected to said link means, a reversible source of pressure fiuid, conduit means connecting said source and actuators in a reversible series fluid flow circuit to effect pressure fluid to flow selectively in one direction through a portion of said conduit means and into one of said actuators on one side of the paddle therein to cause said paddle to move in a first direction in its chamber for a predetermined distance, said paddle movement forcing an equal amount of pressure fluid located ahead of said paddle to flow from said chamber through another portion of said conduit means into the other actuator to cause the paddle therein to also move in said first direction for substantially said predetermined distance, the actuation of said paddles being approximately simultaneous, the movement of said paddle in said other actuator causing the pressure fluid located therein ahead of said paddle to exhaust into still another portion of said conduit means and return to said fluid source, restrictive passage means formed in each said actuator casing in the region of the connection of the conduit means portion at the terminal position of movement of each paddle in each direction, second conduit means connecting each said passage means into each said conduit means portion, one-way valve means in each said second conduit means and operable to permit fluid ahead of each said paddle to flow out of said actuators only, the casing end of each of said passage means being positioned so that the paddle passes over said end as the paddle approaches the respective terminal position thereof.

References Cited by the Examiner UNITED STATES PATENTS 56,898 8/1866 Cabell 91-401 XR 250,643 12/1881 Brust et al 92121 X 683,427 10/1901 Barger 92125 X 1,186,827 6/1916 Pennypacker 92125 1,569,429 1/1926 Lippert 92--125 X 2,141,953 12/1938 Hawes 92--121 X 2,370,376 2/1945 Snell 6052 X 2,509,623 5/1950 Baade 60-52 2,511,501 6/1950 Floraday 92120 X 2,806,451 9/1957 Vinkler et a1. 91401 2,870,556 1/1959 Riddell 92124 X 3,106,064 10/1963 McLeod 6052 3,153,317 10/1964 Manor et al 60--52 X 3,174,405 3/ 1965 Wilkinson 91-1 FOREIGN PATENTS 623,229 5/ 1949 Great Britain.

JULIUS E. WEST, Primary Examiner. 

1. A HYDRAULIC ACTUATOR COMPRISING: A CASING SUBSTANTIALLY SECTOR SHAPED IN LONGITUDINAL CROSS SECTION AND RECTANGULAR SHAPED IN TRANSVERSE CROSS SECTION, A SHAFT EXTENDING INTO THE CASING SUBSTANTIALLY AT THE APEX OF SAID CASING, A PADDLE IN THE CASING SEALINGLY FITTED IN THE CASING AND FIXED TO SAID SHAFT, AND CONDUIT MEANS FOR SELECTIVELY ADMITTING PRESSURE FLUID INTO AND FROM SAID CASING ON RESPECTIVELY OPPOSITE SIDES OF SAID PADDLE EFFECTIVE TO ROTATE SAID SHAFT, SAID CASING COMPRISING TWO SUBSTANTIALLY IDENTICAL SECTOR SHAPED PORTIONS, HAVING UPSTANDING PERIPHERAL WALLS, SAID PORTIONS BEING PLACED TOGETHER WITH THE RESPECTIVE WALLS SUBSTANTIALLY COPLANAR AND IN ENGAGEMENT, AND MEANS SEALINGLY RIGIDLY CONNECTING SAID WALLS TOGETHER, SAID PADDLE HAVING GROOVE MEANS EXTENDING COMPLETELY AROUND THE EDGE OF THE PADDLE AND INCLUDING PORTIONS EXTENDING AROUND OPPOSITE SIDES OF THE SHAFT, AND RESILIENT SEAL MEANS IN SAID GROOVE MEANS TO SEAL THE PADDLE TO THE INTERIOR WALLS OF THE CASING AND INCLUDING THE REGION THEREOF AROUND SAID SHAFT, SAID PADDLE COMPRISING TWO SUBSTANTIALLY IDENTICAL MEMBERS HAVING MARGINAL STEPS THEREON AND PLACED TOGETHER IN FACE TO FACE ENGAGEMENT SO THE SAID STEPS COOPERATE TO FORM SAID GROOVE MEANS, MEANS FIXEDLY SECURING SAID MEMBERS TOGETHER AND TO SAID SHAFT, PORT MEANS IN THE SAID CASING LOCATED ADJACENT EACH TERMINAL POSITION OF SAID PADDLE AND WHICH THE PADDLE PASSES OVER IN MOVING INTO ITS RESPECTIVE TERMINAL POSITIONS, SAID PORT MEANS BEING CONNECTED WITH SAID ASSOCIATED CONDUIT MEANS AND A CHECK VALVE CONNECTED TO EACH PORT MEANS PERMITTING FLUID FLOW FROM EACH PORT MEANS IN A DIRECTION AWAY FROM SAID CASING ONLY. 